OBJECTIVETo investigate the apoptosis-inducing effect of nitidine chloride in human osteosarcoma MG-63 cells and explore its mechanism.

METHODSThe effect of nitidine chloride on the proliferation of MG-63 cells was detected by colorimetric MTT assay, and the morphological changes of cells treated with nitidine chloride were observed using fluorescence and electron microscope. Flow cytometry was performed to analyze the apoptotic rate of the cells, and the protein expression levels of caspase-3, caspase-9, Bcl-2 and Bax were detected by Western blotting.

RESULTSNitidine chloride inhibited the proliferation of MG-63 cells in a dose- and time-dependent manner. Fluorescence and electron microscopy revealed distinct apoptotic changes of the cells after nitidine chloride exposure. Flow cytometry indicated that nitidine chloride induced the apoptosis of MG-63 cells in a dose-dependent manner. Exposure to nitidine chloride, as shown by Western blotting, resulted in increased expressions of cleaved caspase-3, cleaved caspase-9 and Bax and decreased expressions of pro-caspase-3, pro-caspase-9 and Bcl-2.

CONCLUSIONNitidine chloride can inhibit the proliferation of osteosarcoma cell line MG-63 by inducing cell apoptosis, the mechanism of which might be related with the activation of the caspase-dependent pathway.